1. Field of the Invention
This invention relates to coin testing apparatus which may be used, for example, to test coins tendered for the operation of vending machines, telephone coin-boxes or other coin-freed apparatus.
2. Description of the Prior Art
Coin testing apparatus is known. Earlier apparatus was essentially mechanical in operation and therefore complex, expensive to manufacture, and not very reliable. More recently, electronic coin testing apparatus has become available. Electronic apparatus now on the market is subject to a number of disadvantages. One such disadvantage is that the apparatus is designed to test coins on the move, which means that the apparatus must be of relatively complex design. A known electronic apparatus employs light emitting diodes (LEDs) and photosensors in carrying out checks on coins. A disadvantage of this arrangement is that dirt tends to gather on the LEDs thereby blocking the emission of light, whereby the apparatus fails to function correctly and has to be stripped down and cleaned.